Mobile phone networks have traditionally been limited to voice communications, but new technologies such as GSM (Global System for Mobile Communications) have enabled mobile phone networks to also include data communications. For example, SMS (Short Message Service) messaging provides a software-independent protocol to send short text messages composed of either: 160-7 bit characters; 70-16 bit characters; or 140 octets of binary data. Individual SMS messages thus require a relatively small network bandwidth and devices can receive messages, even when connected to a voice call. The number of SMS messages a user receives has continually increased because many new types of network devices have joined mobile phone networks. These devices include, for example, PDAs, hybrid PDA/mobile phone devices, and other text messaging devices using GSM networks. Additionally, PSTN devices also exist that support messaging applications such as SMS.
Numerous other types of messaging exist on such mobile devices. For example, email and Multimedia Message Service (MMS) are alternative types of messages available on many mobile devices.